With the development of computer technology, besides data transmission, more and more powerful functions can be provided via computer networks. For example, cloud computing is a model of service delivery for enabling convenient, on-demand network access to a shared pool of configurable computing resources. At this point, a user does not have to buy a high-performance computing device and install various application programs on the computing device to meet his/her demand, but can obtain needed resources and services via cloud.
For example, the user does not have to install a document editor on a local computer, but rather can view and edit documents using a browser through an online document editor provided by a network service provider. In addition, with the miniaturization and diversity tendency of computing devices, more and more users tend to use portable computing devices (such as tablet PCs, smart phones, personal digital assistants, etc.) for viewing and editing documents. Since hardware configuration of portable computing device is usually low, research has been directed toward providing online document editors for use via portable computing devices.
Though browser-based online document editors have been developed so far, their displaying efficiency tends to be low and they may not be able to display document content at a user-desired speed, and such a long delay during document displaying may lead to bad user experience.